Brush and art of making same



March 18, 1947.

Filed Oct. 14, 1943 3 Sheets-Sheet l March 18, v1947. E. W. HALL l l 2,417,750

' BRUSH AND ART 0F MAKING SAME 5 Sheets-Sheet 2 H M M, WL 24M W Filed Oct. 14. 1945 March 18,1947 E; W, HALL v 2,417,750

BRUSH-AND ART oF MAKING SAME Filed Oct. 14, 1945 3 Sheets-Sheet 3 e 50 .48 /8 /652 46 52 /848 /e /a es l 5o A414/O 5a /6 a /4 .IW/venorf:

E27/@2m Wlfaz z, 535/ fgm/ #MM Patented ar. 18, 1947 4 Claims.

This invention relates to brushes, and to the Application October 14, 1943, Serial No. 506,148 g y The invention will be understood by reference to the following description when taken in con. nection with the accompanying drawings illustrating two` forms of the brush and the steps and apparatus employed in the art of making the brushes, while its scope vwill be pointed out more particularly in the appended claims.

In the drawings:

Fig. 1 is an elevation of one form of brushes embodying the invention;

Fig. 2 is a sectional view on on line 2 2 of Fig. 1;

Fig. 3 is a longitudinal sectional view of a second form of brush embodying the invention;

Fig. 4 is a. sectional view on an enlarged scale on line -Ji of Fig. 3;

Fig. 5 is a plan of a jig for use in assembling bristles as one step in the act oi making the brushes;

Fig. 6 is a plan illustrating the lower half of the mold with the bristles positioned with relation thereto and with a weight resting ,upon the bristles to hold them in place;

an enlarged Y scale Fig. '7 is a vertical sectional view illustrating Y the jig, the lower half of the m'old, the support for the bristles. and the bristles thereon;

Fig. 8 is a similar sectional view after the jig has been removed and a weight has been placed upon the bristles to hold them in place;

Fig. 9 is a top plan of the lower half of the mold, or a bottom plan of the upper half of the nold;

Fig. 10 is a sectional view on line Ill-lll of Fig. l; and

Fig. 11 is a vertical sectional view of the com- Jlete mold with its accessories and with the )rushes in the mold. p Referring to Figs. 1 and 2 of the drawings, there s shown a brush comprising a mass of bristles l2 such as Tampico :ben-for example, having one iet of ends incorporated inl a, molded, adhesive ilastic head lli in such a manner that each inlividual bristle is, firmly anchored without the iecessity of doubling the bristles or employing mechanical fastenings such as wires or pins commonly employed. To this end, I prefer to employ a composition of sawdust, preferably of hard wood such as maple, and a synthetic resin such as an aldehyde (or formaldehyde) urea molding composition which is soluble in water, is highly adhesive, and, when hardened, is waterproof. Its nature is such that it penetrates between and surrounds the individual bristles, thus securely anchoring them. Also securely anchored in the same manner is a handle i6 of wood, for example, having a reduced portion I8 embedded in, surrounded by, and adhesively held by the adhesive plastic. Y

In an alternative construction, shown in Figs. 3 and 4, there is employed a mass of bristles 20 incorporated in like manner in a molded, adhesive plastic head 22, but in this case, instead of employing a separate handle embedded in the head, there is employed a handle 24 which is molded as an integral part of the head 22 andv vhas incorporated in it a group 2S of bristles which are much longer than the others/and are prolonged beyond the head, some of the plastic b'eing molded about the bristles which are so prolonged, so as to make a smooth surface for handling. l

From an examination of Figs. 1- and 3 in comparison with Figs. 2 and 4, it will be observed.

that in each embodiment there are two parallel walls (see Fig. 2, for example) extending from one edge of.u the head to the opposite edge, and that the head has no walls at said edges, but instead, the mass of bristles extends al1 the way l now be described, reference being had at rst to Fig. 5 which shows in plan a bristle positioning tool or jig comprising a disk 28 having a set of radial blades 30 suitably secured rigidly thereto as by fitting them firmly into slots 32. The blades are spaced appropriate angular distances apart to provide pocket 34 of suitable dimensions to receive small assemblies of bristles snugly lling the pockets. In case the integral handle of Figs. 3 and 4 is being made, the groups of longer bristles are received in radial recesses 3G.

-members 44, and engaging evident that these The lling of the pockets may take place at the assembly point where the molding is to take place (see Fig. 1), and the tool or jig is then withdrawn upwardly, leaving the bristles in their proper relation to a mold presently to be described. The bristles are deposited upon a supporting ring 38 resting upon a table or bench 40, and to hold the bristles securely in place during subsequent operations. a weighting ring presently to be described. The mold membersabut face to face as shown at the central part of Fig. 11 about the bolt 48.

Each mold member is provided with a plurality of radially disposed cavities 48 (see Fig. 9) and Y complementary cavities of both mold members are completed by upper and lower rings 50 iirmly afiixed to and forming in effect parts of the mold the bristles firmly enough (see Fig. 11) to prevent escape of any considerable amount of the adhesive plastic. For the emplacement of the separate handles, or for the molding of the integral handles, the cavities 48 are provided with extensions 52 extending radially inward toward the center of the mold. In the present example, these extensions are semi-cylindrical (see Fig. lil) and the complementary parts form cylindrical cavities when the two mold sections are assembled face to face. Figs. 8 and 11 show a separate handle I6 in place in the cavity, and Fig. 11 shows the reduced end I8 incorporated with the bristles i2 in the molded head I4.` When, however, an integral handle is to be molded,`as before stated, the longer group of bristles will extend into the complementary cavity extensions 52. If desired, the several cavities may intercommunicate as by one or more gates such as the gates 54 and 56 to 4permit the iiow of the adhesive plastic from one cavity to another, in which case, after the removal of the casting, the iins produced by the gates are broken and are suitably finished ofi. One or more dowel pins 58 carried by one mold member and projecting into a lcorresponding hole or holes in the other mold member register the mold members properly.

The rst step in the method is to assemble the bristles (or the bristles and the separate handles) as already described. By reference to Fig. 6, it will be observed that each mass of bristles extends all theway from one edge of the cavity 48 to the opposite edge. It will also be observed from an examination of Fig. 11 that the top and bottom of the complementary cavities 48 are separated from the mass of 'bristles l2 by top and bottom spaces which produce upper and lower walls. From an inspection of Fig. 9, it must-.be walls must necessarily extend from one 'edge of the cavity 48 to the opposite edge. From an examination of Fig. 6, it must be evident that the mass of bristles extends all the way from one edge of the cavity 48 to its opposite edge, thus completely filling the cavity from edge to edge and being thereby accurately 4 located and firmly held by said edges during the molding of the head. Second, without the upper mold member in place. a predeterminedv quantity of the described mixture is poured into the cavities of the lower mold member, the quantity being suicient to illl the complementary cavities completely, the mixture being so thick that it will stand up from the lower mold member sufliciently to iill the upper mold member, also. The third step is to place the upper mold member on and about the bolt 48 and to allow the same to descend upon the plastic mixture. The fourth step is to place a nut 60 (see Fig. 11) on the bolt 46 and to screw the nut down until the confronting faces of the mold members 44 abut against each other. Meantime, the mixture fills the mold completely and flows about those portions of the bristles which extend into the mold, and also about the reduced portions of the separate handles if separate handles are employed, hence firmly uniting each individual bristle, as well as the separate handles, with the brush heads.

The fth step is to apply heat as by infra-red rays to the brushes while in the mold. It has been found that one and one-halfhours of this treatment is sufficient. Heat may be otherwise applied as by oven, unit heaters or ultra high frequency elds. The casting is then removed from the mold and is aged for a time to acquire maximum strength, after which the brushes are broken apart and finished as by sanding.

Having thus described the invention, what I claim and desire by Letters Patent to secure is:

l. In a brush, the combination of a mass of individual bristles, and a holder therefor comprising a handle and a molded, adhesive plastic head in which one set of ends of said bristles are incorporated and held solely by the individual bristles being surrounded by the adhesive plastic, said head having two parallel walls extending from one edge to another edge, and said mass also extending from the rst-named edge to the second-named edge between said walls and exposed at said edges.

2. In a brush, the combination of a mass of individual bristles, and a holder therefor comprising a unitary, molded adhesive plastic handle and a head in which head one set of ends of said bristles are incorporated and held solely by the individual bristles being surrounded by the adhesive plastic, some of said bristles being prolonged beyond said head and incorporated in said handle, said head having two parallel walls extending from Aone edge to another edge, and

f' said mass also extending from the first-named edge to the second-named edge between said walls and exposed at said edges.

. 3. In a brush, the combination of a mass of individual bristles, and a holder therefor comprising a unitary, molded, adhesive plastic handle and a head in which head one set of ends of said bristles are incorporated and held'y solely by the individual bristles being surrounded by the adhesive plastic, some of said bristles being prolonged beyond said head and incorporated in said handle, and some of the plastic being molded about the bristles which are so prolonged, said head having two parallel walls extending from one edge to another edge, and said mass also extending from the first-named edge to the secondnamed edge between said walls and exposed at said edges.

4. In the art of making brushes, the steps of placing long and short sets of bristles each with a set'of ends extending'into a-cavity and molding a. plastic substance about said long sei: of bristles to form a handle and aiboutsaid short; set of bristles to form a head. Number ELISHA W. HALL.

REFERENCES CITED The following references are of record in vthe` le of this patent:

6 UNITED STATES PATEN'I'S Kane July 2, 1895 

